Methadone is a strong opioid but at the same time significant non-competitive NMDA-receptor antagonist qualities have been described. Many small studies and case-reports describe the successful rotation from different strong opioids to methadone. There are no studies that selected patients with (predominantly) neuropathic pain to be treated with methadone, whereas this group of patients is expected to profit from the NMDAR-antagonist properties of methadone.